Have a 330d sport2004 model (204bhp) with 52k miles, had the car rempaapped around 40k; i can hear a slight whistling noise coming from the engine or turbo?; when i lift my foot of the acclerator.
Does anyone know what could be causing this noise.
Thanks.

If you hear the noise while the car is idling, its the turbo going for a crap.
It can whistle if you leave the pedal, it can be the dumpvalve but that's normal.
Depend on the nature of the whistle you are talking about.